Pivotable self-centering elastomer pressure-wafer probe

Abstract

A test probe for testing an integrated circuit formed on an integrated circuit die. The probe comprises a printed circuit board interface having an opening in its center. A flexible membrane is formed on a bottom surface of the printed circuit board interface that is flexible in the middle thereof. A plurality of electrical traces and a plurality of bumps are formed on the flexible membrane that terminate at a plurality of termination pads that permit interfacing of the integrated circuit to the external test equipment. A clear plastic window is secured to the printed circuit board interface an a portion thereof protrudes into the opening in the interface. A cone shaped retainer having a circular opening at its center that abuts a bottom surface of the clear plastic window. A pivotable elastomer member having a truncated conical cross section abuts the bottom surface of the clear plastic window. A clear plastic pressure and pivot plate is disposed between the flexible membrane and a bottom surface of the pivotable elastomer member. When the probe is assembled, the flexible membrane is disposed in its flexed position, extending outward relative to the non-flexible portion thereof. The flexible membrane is moved into its flexed position by the force created by the force exerted thereon by the pivotable elastomer member and clear plastic pressure and pivot plate. The elastomer member compresses during interconnection to the integrated circuit, and deflects, as required, to permit tilting of the flexible membrane and thus proper mating of the bumps and pads on the integrated circuit. Upward movement of the die and integrated circuit provides the force to ensure contact between the bumps and pads and to tilt the flexible membrane when required. The probe is especially suitable for very small integrated circuit die patterns, such as are used in testing die whose die patterns are less than 250 inches square.

What is claimed is: 
     
       1. A test probe for testing an integrated circuit formed on an integrated circuit die, said probe comprising: a printed circuit board interface having an opening at its center;   a flexible membrane formed on a first surface of the printed circuit board interface and which is flexible in the middle thereof adjacent the opening;   a plurality of electrical traces disposed on the printed circuit board interface that provide for electrical connection to the integrated circuit;   a window secured to a second surface of the printed circuit board interface that has a portion thereof that extends into the opening therein;   a retainer having an opening at its center that is secured to the window;   a elastomer member that abuts the window; and   a pressure and pivot plate disposed between the flexible membrane and the pivotable elastomer member.   
     
     
       2. The test probe of claim 1 wherein the window is comprised of clear plastic. 
     
     
       3. The test probe of claim 1 wherein the window is comprised of acrylic. 
     
     
       4. The test probe of claim 1 wherein the retainer is cone shaped and has a stepped cross section with sloped outer and inner walls. 
     
     
       5. The test probe of claim 1 wherein the flexible membrane is comprised of copper coated polyimide. 
     
     
       6. The test probe of claim 1 wherein the printed circuit board interface is comprised of fiberglass. 
     
     
       7. The test probe of claim 1 wherein the retainer is comprised of stainless steel. 
     
     
       8. The test probe of claim 1 wherein the elastomer member is comprised of silicone. 
     
     
       9. The test probe of claim 1 wherein the pressure and pivot plate is comprised of clear plastic. 
     
     
       10. The test probe of claim 1 wherein the pressure and pivot plate is comprised of glass. 
     
     
       11. A test probe for testing an integrated circuit formed on an integrated circuit die, said probe comprising: a printed circuit board interface having an opening at its center;   a flexible membrane formed on a first surface of the printed circuit board interface and which is flexible in the middle thereof adjacent the opening in the printed circuit board interface;   a plurality of electrical traces disposed on the printed circuit board interface that terminate at one end in a plurality of bumps that provide for electrical connection to the integrated circuit, and that terminate at opposite ends at a plurality of termination pads that permit interfacing of the integrated circuit to external test equipment;   a clear window secured to a top surface of the printed circuit board interface that has a portion thereof that extends into the opening in the printed circuit board interface;   a cone shaped retainer having a circular opening at its center that is secured to a bottom surface of the clear window;   a pivotable elastomer member that abuts the bottom surface of the clear window; and   a clear pressure and pivot plate disposed between the flexible membrane and the pivotable elastomer member.   
     
     
       12. The test probe of claim 11 wherein the pivotable elastomer member has a truncated conical cross section. 
     
     
       13. The test probe of claim 11 wherein the clear window is comprised of acrylic. 
     
     
       14. The test probe of claim 11 wherein the cone shaped retainer is circular and has a stepped cross section with sloped outer and inner walls. 
     
     
       15. The test probe of claim 11 wherein the flexible membrane is comprised of copper coated polyimide. 
     
     
       16. The test probe of claim 11 wherein the printed circuit board interface is comprised of fiberglass. 
     
     
       17. The test probe of claim 11 wherein the cone shaped retainer is comprised of stainless steel. 
     
     
       18. The test probe of claim 11 wherein the pivotable elastomer member is comprised of silicone. 
     
     
       19. The test probe of claim 11 wherein the clear pressure and pivot plate is comprised of clear plastic. 
     
     
       20. The test probe of claim 11 wherein the clear pressure and pivot plate is comprised of glass.